The invention relates generally to void fillers or dunnage devices, expandable when suspended to form a honeycomb slab, or cellular array. More specifically, a honeycomb slab of simplified construction exhibiting both superior strength and an improved expanded configuration is disclosed.
After articles of freight have been loaded into railroad boxcars or other shipping containers, space voids often remain between adjacent stacks of goods or between stacks of goods and a nearby wall. If these voids are not filled, the contained articles may shift during transit, possibly damaging the goods or the walls and doors of the container. Specialized dunnage to fill these voids has assumed a unitized honeycomb or cellular construction, compressible into a short stack for storage and expandable into an elongated array for actual use. The honeycomb slab itself is commonly assembled from sheet material, such as corrugated paperboard. A hanging mechanism, usually resting upon the stacks of freight articles or attached to an adjacent wall, suspends the honeycomb slab for expansion downwardly under its own weight.
Owing to the orientation of the paperboard corrugations, the honeycomb slab exhibits considerable resistance to forces applied normal to the faces of the slab, and little resistance to forces acting normal to the edges of the slab. Thus, individual cells, especially within the median portion of the structure, distend or elongate in a vertical aspect when the array is suspended. Consequently, the honeycomb slab of conventional design has a tendency to narrow in its median portion, or assume an hourglass shape, creating voids into which articles of freight may slide or shift.
In Bramlett, U.S. Pat. No. 3,593,671, rigid sheet members are shown transversely positioned within certain of the cells, to restrict horizontal contraction and undue vertical elongation of the honeycomb slab. U.S. Pat. No. 4,007,309, issued to Sewell, illustrates another approach, employing a number of stiff strips of corrugated paperboard interspersed throughout the slab, their corrugations extending from edge to edge of the slab. The present invention represents a further improvement over these designs in that simplified construction, increased strength, and linear shape of the expanded honeycomb slab are offered.